Flip-chip package structure with block bumps and the wedge bonding method thereof

Abstract

A flip-chip block structure with block bumps comprises a die, a substrate, a first block bump, and a second block bump. The die comprises an active side and a backside, a first die pad and a second die pad are disposed on the active surface, and an electrode layer is disposed on the backside. The first die pad and the second die pad are connected to the pattern side of the substrate via the first block bump and the second block bump respectively. Besides, the first block bump and the second block bump are formed by a wedge bonding method, therefore, the block bumps are more easily formed into larger sizes, which enhance electrical performance and thermal dissipation performance of the flip-chip structure due to a lower contact resistance and a larger contact area between the die and the substrate.

1 . The wedge bonding method to form a block bump on a die with a die bond pad, comprising:
 providing a metal wire;   forming a wedge bond on the die bond pad of the die by wedge bonding said metal wire; and   breaking the connection between the metal wire and the wedge bond to form the block bump.   
     
     
         2 . The wedge bonding method of  claim 1 , wherein the wedge bond formed by the wedge bonding is completed by a metal diffusion technology. 
     
     
         3 . The wedge bonding method of  claim 2 , wherein the metal diffusion technology adopts an ultrasonic bonding, a thermal-sonic bonding or a thermal-compress bonding.